1. Field of the Invention
The invention relates to a method and apparatus for processing shucked scallops to remove the viscera from the edible muscle.
2. Description of the Related Art
Shellfish processing can take place either on board ship or ashore. To open the shell to retrieve the fish, the shell is placed in fresh water for 6 to 8 hours and then in boiling water for a short period (see U.S. Pat. No. 3,662,432). The contents of the shell are then retrieved for further processing. With bi-valves such as scallops, only one muscle is used for human consumption. That muscle, which is identified by consumers as the scallop, is the adductor muscle which opens and closes the shell. The shellfish's organs and other inedible portions of the shellfish, called the viscera, are attached to the scallop after the shell has opened in the hot bath. The viscera must be cleaned from the scallop to produce an edible product.
In general, one method of cleaning scallops is commonly used. This method tears the viscera or innards from the scallop by rubbing the muscle and attached viscera against a rough surface. Because the scallop is firmer than the viscera, the rough surface engages and removes the viscera from the scallop.
Numerous methods are known for removing the innards in this manner. Reference can be made in that regard to U.S. Pat. Nos. 3,129,456, 3,257,684, 3,528,124, 3,562,855, 3,662,432, 3,665,554, 3,665,555, RE 31,527, 3,802,029 and 4,675,946.
While the processes disclosed in each of the above-listed patents each provide a means for removing the viscera from the scallop muscle, each of those processes exhibits certain deficiencies.
U.S. Pat. No. 4,675,946 to Bunge, the disclosure of which is incorporated herein by this reference, advantageously overcomes many of the deficiencies encountered with prior scallop processes. That is not to say that the Bunge process and apparatus cannot be improved and, in fact, the present invention constitutes an improvement in the Bunge processing concept and structure.
The Bunge structure includes a cylindrical drum or trommel defined by a plurality of elongated rollers having axes parallel to the axis of the drum. A drive mechanism is provided for driving the cylindrical drum to rotate about its longitudinal axis. At the same time, the rollers defining the cylindrical drum are rotated by a drive mechanism which causes alternating rollers to rotate in opposite directions. The rollers are covered with a frictional or roughened material to grip the viscera and pull it from the edible muscle and pass it outwardly of the cylindrical drum.
As noted above, the Bunge structure has certain deficiencies. For example, it is necessary to provide a complex discharge mechanism at the downstream end of the trommel for removing the cleaned scallops from the trommel. Furthermore, as the trommel rotates, there is a possibility that some scallops will travel through the length of the trommel very quickly without having the opportunity to contact with the rubbing material and, therefore, without proper cleaning.
It would therefore be desirable to provide a method and apparatus for eviscerating scallops, of generally the type described in Bunge but which includes a structure for reliably propelling the scallops along the length of the apparatus and from which the cleaned scallops can be removed without difficulty, while keeping the scallops in the trommel sufficiently in contact with the rubbing area to allow for sufficient cleaning.